I have written a simple WebService Client. The WebService expects that the WebService clients enable HTTP compression. This is the exact text from the docs:-

""1. Client should be HTTP Compression enabled
HTTP Compression had been made mandatory for APIís. Thus APIís client should
include ďAccept-Encoding: zipĒ header as part of request and should be able to
handle compressed data. Please note that system will send an error message if client
are not http compression enabled saying client should be compression enabled."

I do not know how to enable HTTP compression in the WebService Client. The method called is "GetInstantaneousFlowData". It accepts no arguments and returns xsd:datetime.